"Could this replace the Zaurus?"
Beautiful children! Now RTFA!
This is the nearest I've seen HTC come to producing a worthy successor to the uni, but it's not what I'm waiting for. The article teases us by hinting that HTC do have a true uni successor in the works but says no more on that.
For me the flipstart looks to be the most worthy successor to the c3x00 series. I just hope it has build quality to match the Z, decent battery life (can't see it to be honest, but...) and isn't too expensive (again, can't see it being cheap on launch). I reckon I'll be sticking with my c3100 for a couple of years yet.